The Technology: I am developing a new kind of piezoresistive strain sensor capable of
sustaining strains up to at least 25% and
with a gauge factor far greater than that found in traditional resistive gauges. The sensor is
designed as an elastomer-nanotube
composite that deliberately avoids the major failure modes of traditional resistive strain gauges.
In addition to improved elasticity
and sensitivity, this type of sensor can be shaped into nearly any configuration and embedded in a
variety of polymers. These
attributes are particular important given that the application is to monitor forces in engineered
muscle.
The Application: I am designing my sensors to be integrated into engineered sheets of cardiac
muscle. We have long been able
to grow sheets of cardiac muscle, and the eventual goal is to implant these as 'patches' over
damaged regions of the heart in
order to improve function. However, despite extensive animal work having been performed, there are
major difficulties, one of
which is addressed by my sensor. Specifically, there are currently no reliable methods for testing
the contractility of engineered
muscle. The result is that there is absolutely no standardization in terms of the properties of the
implants, nor is there any way of
even evaluating different engineering approaches in terms of performance. By incorporating my
sensors into a material
commonly used as a support structure for engineered muscle, I am hoping to be able to monitor 'vital
signs' (contractile force, in
this case) during the development of the tissue.